KENNEDY SPACE CENTER, FLA. - In the Orbiter Processing Facility at Kennedy Space Center in Florida, the payload bay doors of the orbiter Atlantis are being closed. The Remote Manipulator System, or Shuttle arm, is seen on the port side (top) and the Orbiter Boom Sensor System (OBSS) is seen on the starboard side (lower) of the payload bay. The 50-foot-long OBSS attaches to the Shuttle arm and is one of the new safety measures for Return to Flight. It equips the orbiter with cameras and laser systems to inspect the Shuttle?s Thermal Protection System while in space. Atlantis is scheduled to fly on the second Return to Flight mission, STS-121, targeted for launch in a window extending from Sept. 9 to Sept. 24.